Influence of electrochemical doping on low frequency noise of conducting poly(3-methylthiophene) film

Low frequency noise properties of the poly(3-methylthiophene) film prepared by electrochemical polymerization on two-band Pt electrode are investigated. The relation between flicker noise and conducting properties under different doping potential is discussed on the basis of the Hooge empirical equation. Under light doping state, the Hooge parameter almost remains constant with increasing doping potential. However, in the case of heavy doping, it increases with doping potential. The dependence of the Hooge parameter on doping level reflects the evolution of metallic domains and the transport process of charge carriers. It is believed that the amorphous structure and high carrier concentration in the poly(3-methylthiophene) film lead to a greater Hooge parameter value.